Disclosed is an improved splicing nut of the type having a threaded nut portion and a core that is capable of being threaded into the nut portion, the nut portion and the core cooperating to receive and firmly retain a line therein. In the first embodiment of the invention, a visualization port is included in the core for providing visual access to at least a portion of the area between the nut portion and the core so that a user may quickly ascertain by looking through the visualization port whether or not a line is fully engaged with the splicing nut. Additional provision is made to cause the line to be compressed when the core is threaded into the nut portion and tightened. As a result, line slippage within the splicing nut is prevented. The invention further includes a fastening portion of the core that is exposed when the nut portion is firmly tightened onto the core. Either a pin hole or a shackle fastening means is included in the fastening portion for allowing additional hardware to be installed thereon with requiring the line to be removed from the splicing nut.